The invention relates to a hydraulic main brake cylinder of the general type described by the preamble to the main claim.
There are several possible ways of combining an anti-locking apparatus of the kind having magnetic valves and switching pistons with a hydraulic main brake cylinder.
First possibility:
A separate hydro-unit for the anti-locking function with an appropriate energy supply, and a conventional brake force amplifier therefor with energy supply effected via underpressure or an underpressure pump. In place of the underpressure amplifier, a hydraulic amplifier can also be used.
Second possibility:
A separate hydro-unit for the anti-locking function and a common energy supply for the hydro-unit, anti-locking means and brake force amplifier. In this case, the brake force amplifier is in the practical sense purely hydraulic.
Third possibility:
In the application of an external-force brake system, it is conceivable for the anti-locking adjustment members for pressure modulation additionally to be housed in the brake valve block.
In the case of auxiliary-force brake systems, the simplest and most elegant possibility of realization is to utilize the main brake cylinder piston for the purpose of anti-locking pressure modulation as well. An apparatus of this kind is known from German laid-open application No. 27 02 819, for instance which corresponds to U.S. application Ser. No. 133,725 which is a continuation of Ser. No. 870,784, abandoned.
Fourth possibility:
Integration of the anti-locking functions in existing main brake cylinders whose function is unchanged. The integration of, for instance, plunger pistons with magnetic valves directly in the main brake cylinder would be conceivable. This realization, however, would be so expensive in terms of costs as well as structural volume that it could not be integrated into existing vehicle concepts.